1. Field of the Invention
The present invention generally relates to ink jet printing, and particularly to a class of black dyes composition for improving ink-jet light-fastness.
2. Description of the Related Prior Art
Ink jet printing is a non-impact printing method, the involving features include and provide sharp, non feathering patterns, as well consist of good water-fastness, light-fastness, and optical density. Properties such as fast drying and fine storage stability, fine fluency of ink flow, and non-clogging are also included.
Examples of the reactive dyestuffs used: When C.I. Reactive Red 180 or C.I. Reactive Black 31 from the publicized Color Index are used as the dye components of the inkjet printing ink, with time the reactive groups undergo hydrolysis, which then results in an increase amount of salts in the ink as hydrolysis proceeds, the consequences of are clogging at the nozzle or variability of the hue of the ink and others.
In the U.S. Pat. No. 4,694,302 and U.S. Pat. No. 5,062,892, the commonly used black ink dye composition such as C.I. Food Black 2 is disclosed, where the light-fastness and other properties are poor and the above printing required is not satisfied; and even though the C.I. Direct Black 168 consists of good light-fastness but it has low solubility, so that the use as the inkjet ink dye components is constrained.
As a result, the effort for a dye composition of the ink-jet printing ink with good light-fastness, wide area of color space, good solubility and fine fluency of ink flow is a direction to keep working with.